Preliminary Magnitude and Distance Damage Thresholds for Light-Frame Wood Buildings in Induced Earthquakes

Abstract

Since 2009, the frequency of (moment) magnitude (Mw) 3.0 earthquakes and larger in the Central United States, and especially Oklahoma (OK), has risen from an average of 2 per year, to 200-700 per year. This increase in seismicity is a result of injection of large quantities of wastewater generated from oil and gas activities deep underground. In this study, damage to built infrastructure from induced earthquakes is investigated through nonlinear dynamic analysis and probabilistic damage assessment for a light-frame wood structure. Specifically, we focus here on investigating the smallest Mw injectioninduced earthquake that may cause damage to the building of interest at various distances from the hypocenter (R). The simulations are based on a two-story multifamily dwelling, which is designed with lateral strength and detailing consistent with modern code requirements in Pawnee, OK. For a Mw 4.5 earthquake, damage is observed at R = 15 km or closer. While for an earthquake R = 3 km from the site, damage is observed 56% of the time at Mw 4.5 and occurs 100% of the time when Mw 5.5 and above.